The present invention relates generally to improved supplements for pelleting feeds and more particularly to novel artificial binding ingredients for pelleting feeds based, in part, on a water soluble lignin sulfonate.
Pelleted feeds, which have been defined as agglomerated feeds formed by extruding individual ingredients or mixtures by comparting and forcing through die openings by any mechanical process, are widely used as feed for animals and poultry. It is well known that animals make better weight gains when fed on pelleted feed than when fed on a meal ration for the following reasons:
1. The heat generated in conditioning and pelleting makes the feedstuff portion more digestable by breaking down the starch components therein; PA1 2. Pelleted feeds allows animals and poultry to better utilize the nutrients in the feed ingredients; PA1 3. The pellet simply places the feed in a concentrated form; PA1 4. Pelleting minimizes waste during the eating and consumption process; PA1 5. Pelleting reduces the segregation in mixing, handling and feeding processes; therefore each animal receives a well-balanced diet by preventing the animal from its tendency to pick and choose between a number of ingredients placed before it. PA1 A. Drying and grinding a quantity of peat, particularly reed sedge peat until granular particles are obtained ranging in size between about 10 mesh and 50 mesh to obtain a solid granular feedstuff-filler component; PA1 B. Admixing a liquid binding substance to the solid granular feedstuff-filler to coat the solid particles with liquid binder and impregnate the surface layer of filler particles; PA1 C. Drying the resultant blend at a temperature within the range 190.degree. to 300.degree. to obtain a dried solid granular binding agent, containing about 2-5 percent water; PA1 D. Cooling the resulting product to temperature less than 150.degree., then classifying and grinding it to obtain binder particles of various size, as desired.
The basic purpose of pelleting is to take a finely divided, sometimes dusty, unpalatable and difficult-to-handle feed material and, through the use of heat, moisture and pressure, form it into large particles, which have better flow and handling characteristics and which are normally more palatable. Bulk density and properties relating to shipping are also increased which enhances storage capabilities of most bulk facilities and contributes to a reduction in transportation costs.
Feed ingredients normally comprise formulations of various compounds such as proteins, acids, guars, fibers and minerals. Various ingredients have characteristics that require different forms and levels of heat-moisture treatment during the pelleting operation. When a sufficiently large and controlled compressive force is applied to the "conditioned" feed ingredients they form a dense mass shaped to conform to the die against which they are pressed. After drying and cooling, the resultant shaped mass (the pellet) retains its shape and density and is of such "toughness" as to withstand moderately rough handling without excessive fracture, rupture or breakage, and additionally it has retained or enhanced its nutritive value.
In many cases, adequate pellet quality is not obtained through proper heat-moisture conditioning and die selection, and a binder must then be added to the feed. Two of the most widely used binders are bentonite and lignin sulfonate, with these materials normally being powderized or pulverulent solids in dried form. Unfortunately, the incorporation of high hygroscopic binders such as lignin sulfonate powder into pelleted feed formula normally leads to mixes and finished pellets having properties contributing to poor storage characteristics. Often it is difficult to handle dusty or powdered binding ingredients and it is furthermore difficult to remove them from bulk bins because of resultant caking and bin set up. Frequently, pelleting rates and pellet quality are reduced because it is not always possible to provide the adequate blending and uniform distribution of pulverized binder materials through the mixture mass. Even when well blended with the other ingredients and uniformly distributed among relatively large particles of the other ingredients, the adhesive characteristics and binding efficiency of powdery binders are relatively low due to "volumetric" nature of such binding agents.
Indeed, the large quantity or portion of the powdery binder material in the center or core part of intergranular space filled with binder does not and cannot participate in the binding function. At the same time these particles prevent steam penetration of the blended feed formula mixture. From an analysis of physical principles of pelleted grain structures with binders, it can be seen that the most efficient binding system can be obtained with the aid of particulate elements coated with binding layer and distributed uniformly over the feed mass. Therefore, better pellet quality can be produced using the binder ingredient in granular form rather than in powder-like form and with the binder component thereof being maintained on the outer surface of the granules. Furthermore, the size of the binder particles should be commensurate with the particles of the regular formula feed ingredients. Also, because the artificial binder add to the cost of a feed, they must be used in limited amounts of proportions. Hence, a binding product can be composed of certain low cost filler particles coated with relatively thin film or layer of a binding layer substance.